Abstract Medication safety is an important concern in hospital Emergency Departments (EDs), which provide approximately 136 million patient visits annually in the US and are a common site of care for health disparity populations. In more than one-third of ED visits, patients are unable to provide an accurate list of their medications. Discrepancies and other errors in the documented medication list affect diagnostic and treatment decisions in the ED, and increase the risk of harmful adverse drug events. Taking an accurate medication history and performing medication reconciliation, though required by regulatory agencies, remains a challenge in this time-pressured environment, and new approaches are needed. PictureRx is an internet-based technology that was developed to improve medication management in vulnerable populations. The project team has successfully completed development and feasibility studies, supported by two Phase I SBIR awards from NIMHD. The current platform allows subscribers to manually maintain structured medication lists and print evidence-based, patient-centered illustrated medication lists in English or Spanish. These were shown in a randomized controlled trial to improve medication understanding. The goals of this Phase II research and development proposal are to expand the capabilities of the PictureRx platform by linking to other electronic health data sources, to test its effectiveness in improving medication reconciliation in Emergency Departments, and to enhance its commercial potential as a technology to improve the care of health disparity populations. In Aim 1, we will develop a process for importing patient prescription data from Surescripts (the nation's largest clinical information network) into the PictureRx platform, where it will be automatically filtered and structured using language processing rules. In Aim 2, we will further develop the current PictureRx user interface to facilitate review, verification, and editing of this information by either the patient or a health care professional. We will also build in a series of prompts to gather a more complete medication history from the patient, which the user will input into the PictureRx platform to augment the medication data that can be obtained through automated means. In Aim 3, we will test the effectiveness of the PictureRx technology in enhancing medication safety in clinical practice, where we expect it will improve the accuracy and efficiency of obtaining a medication history from patients in the ED. Patients will also be provided PictureRx medication instructions upon discharge, which we expect to improve understanding. This work involves clinical partnerships with health systems that serve disparity populations. This work will be performed by an experienced team of software engineers, business developers, and academic physicians, who have successfully completed many other projects in technology development and medication safety. The PictureRx technology has very high potential as an effective, affordable, and appropriate intervention to improve care in disparity populations.